# License Agreement

Serial Studio uses a dual-license model to balance open source collaboration with commercial sustainability. This page explains both license types, what each one allows, and where to find the full legal text.

## Dual licensing

### GNU General Public License v3.0 (GPLv3)

The GPLv3 covers the open source portions of the Serial Studio codebase. It applies when all of these are true:

- The build is compiled from source.
- No Pro modules are included.
- All linked dependencies (including Qt) are GPL-compatible.

Under GPLv3 you can use, study, modify, and redistribute Serial Studio freely, but any derivative work has to be released under GPLv3 as well. There is no warranty.

Full text: `LICENSES/GPL-3.0-only.txt`
Reference: <https://www.gnu.org/licenses/gpl-3.0.html>

### Serial Studio Commercial License

The Commercial License covers all official pre-built binaries, builds that include Pro modules, and any commercial use of Serial Studio. It's required for:

- Commercial, institutional, or enterprise deployment.
- Redistribution of official builds.
- Access to Pro-gated features (MQTT, Modbus, CAN Bus, MDF4 export, 3D visualization, XY plotting, and the licensing subsystem).

A Commercial License is sold per user or seat at <https://serial-studio.com>. It lets you use Serial Studio in proprietary projects with no obligation to share your project's source code. Priority support is included.

Full text: `LICENSES/LicenseRef-SerialStudio-Commercial.txt`

### Full license agreement

The central legal document covering both license types is `LICENSE.md` in the project root. It details:

- The dual-license structure and where the boundaries lie.
- Trial limitations and the activation policy.
- Qt licensing requirements for redistribution.
- The Contributor License Agreement (CLA).
- Trademark use and forking restrictions.
- Enforcement and DMCA policy.

## What you can do

- Use the GPL version for personal, educational, and open source projects.
- Modify and redistribute the source code under GPLv3.
- Use the Pro version commercially with a valid Commercial License.
- Evaluate Pro features during the 14-day trial.
- Contribute code under the terms of the CLA.

## What you cannot do

- Use official binaries beyond the trial without buying a license.
- Remove or bypass license checks or activation mechanisms.
- Redistribute Pro binaries without written authorization.
- Include or link Pro modules into a GPL build.
- Use Pro features in commercial or enterprise settings without a Commercial License.

## Contributor License Agreement (CLA)

All contributors need to sign a CLA before their pull requests can be merged. The CLA:

- Grants the maintainer the right to license your contributions under both GPLv3 and the Commercial License.
- Confirms you hold the legal rights to your contributions.
- Lets your code ship in both open source and proprietary builds.

## Feature comparison

For a breakdown of features available under each license tier, see [Pro vs Free Features](https://serial-studio.com/help/pro-vs-free.md).

## License files

- `LICENSE.md`: full dual-license agreement.
- `LICENSES/GPL-3.0-only.txt`: GPLv3 license text.
- `LICENSES/LicenseRef-SerialStudio-Commercial.txt`: Commercial License terms.

For commercial licensing or legal questions, email alex@serial-studio.com.

## See also

- [Pro vs Free Features](https://serial-studio.com/help/pro-vs-free.md): detailed feature comparison.
- [Earn a Pro License](https://serial-studio.com/help/earn-pro-license.md): contribute for free access.
- [Support Serial Studio](https://serial-studio.com/help/support-serial-studio.md): other ways to help.
- [Buy Serial Studio Pro](https://store.serial-studio.com/): purchase a Pro license.